/*
 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

/*
 *
 *
 *
 *
 *
 * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 *  * Neither the name of JSR-310 nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package java.time.chrono;

import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_MONTH;
import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_YEAR;
import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_MONTH;
import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_YEAR;
import static java.time.temporal.ChronoField.DAY_OF_MONTH;
import static java.time.temporal.ChronoField.DAY_OF_WEEK;
import static java.time.temporal.ChronoField.DAY_OF_YEAR;
import static java.time.temporal.ChronoField.EPOCH_DAY;
import static java.time.temporal.ChronoField.ERA;
import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
import static java.time.temporal.ChronoField.PROLEPTIC_MONTH;
import static java.time.temporal.ChronoField.YEAR;
import static java.time.temporal.ChronoField.YEAR_OF_ERA;
import static java.time.temporal.ChronoUnit.DAYS;
import static java.time.temporal.ChronoUnit.MONTHS;
import static java.time.temporal.ChronoUnit.WEEKS;
import static java.time.temporal.TemporalAdjusters.nextOrSame;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.ObjectStreamException;
import java.io.Serializable;
import java.time.DateTimeException;
import java.time.DayOfWeek;
import java.time.format.ResolverStyle;
import java.time.temporal.ChronoField;
import java.time.temporal.TemporalAdjusters;
import java.time.temporal.TemporalField;
import java.time.temporal.ValueRange;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Objects;
import java.util.ServiceLoader;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import sun.util.logging.PlatformLogger;

/**
 * An abstract implementation of a calendar system, used to organize and identify dates.
 * <p>
 * The main date and time API is built on the ISO calendar system.
 * The chronology operates behind the scenes to represent the general concept of a calendar system.
 * <p>
 * See {@link Chronology} for more details.
 *
 * @implSpec This class is separated from the {@code Chronology} interface so that the static
 * methods are not inherited. While {@code Chronology} can be implemented directly, it is strongly
 * recommended to extend this abstract class instead. <p> This class must be implemented with care
 * to ensure other classes operate correctly. All implementations that can be instantiated must be
 * final, immutable and thread-safe. Subclasses should be Serializable wherever possible.
 * @since 1.8
 */
public abstract class AbstractChronology implements Chronology {

  /**
   * ChronoLocalDate order constant.
   */
  static final Comparator<ChronoLocalDate> DATE_ORDER =
      (Comparator<ChronoLocalDate> & Serializable) (date1, date2) -> {
        return Long.compare(date1.toEpochDay(), date2.toEpochDay());
      };
  /**
   * ChronoLocalDateTime order constant.
   */
  static final Comparator<ChronoLocalDateTime<? extends ChronoLocalDate>> DATE_TIME_ORDER =
      (Comparator<ChronoLocalDateTime<? extends ChronoLocalDate>> & Serializable) (dateTime1, dateTime2) -> {
        int cmp = Long
            .compare(dateTime1.toLocalDate().toEpochDay(), dateTime2.toLocalDate().toEpochDay());
        if (cmp == 0) {
          cmp = Long.compare(dateTime1.toLocalTime().toNanoOfDay(),
              dateTime2.toLocalTime().toNanoOfDay());
        }
        return cmp;
      };
  /**
   * ChronoZonedDateTime order constant.
   */
  static final Comparator<ChronoZonedDateTime<?>> INSTANT_ORDER =
      (Comparator<ChronoZonedDateTime<?>> & Serializable) (dateTime1, dateTime2) -> {
        int cmp = Long.compare(dateTime1.toEpochSecond(), dateTime2.toEpochSecond());
        if (cmp == 0) {
          cmp = Long.compare(dateTime1.toLocalTime().getNano(), dateTime2.toLocalTime().getNano());
        }
        return cmp;
      };

  /**
   * Map of available calendars by ID.
   */
  private static final ConcurrentHashMap<String, Chronology> CHRONOS_BY_ID = new ConcurrentHashMap<>();
  /**
   * Map of available calendars by calendar type.
   */
  private static final ConcurrentHashMap<String, Chronology> CHRONOS_BY_TYPE = new ConcurrentHashMap<>();

  /**
   * Register a Chronology by its ID and type for lookup by {@link #of(String)}.
   * Chronologies must not be registered until they are completely constructed.
   * Specifically, not in the constructor of Chronology.
   *
   * @param chrono the chronology to register; not null
   * @return the already registered Chronology if any, may be null
   */
  static Chronology registerChrono(Chronology chrono) {
    return registerChrono(chrono, chrono.getId());
  }

  /**
   * Register a Chronology by ID and type for lookup by {@link #of(String)}.
   * Chronos must not be registered until they are completely constructed.
   * Specifically, not in the constructor of Chronology.
   *
   * @param chrono the chronology to register; not null
   * @param id the ID to register the chronology; not null
   * @return the already registered Chronology if any, may be null
   */
  static Chronology registerChrono(Chronology chrono, String id) {
    Chronology prev = CHRONOS_BY_ID.putIfAbsent(id, chrono);
    if (prev == null) {
      String type = chrono.getCalendarType();
      if (type != null) {
        CHRONOS_BY_TYPE.putIfAbsent(type, chrono);
      }
    }
    return prev;
  }

  /**
   * Initialization of the maps from id and type to Chronology.
   * The ServiceLoader is used to find and register any implementations
   * of {@link java.time.chrono.AbstractChronology} found in the bootclass loader.
   * The built-in chronologies are registered explicitly.
   * Calendars configured via the Thread's context classloader are local
   * to that thread and are ignored.
   * <p>
   * The initialization is done only once using the registration
   * of the IsoChronology as the test and the final step.
   * Multiple threads may perform the initialization concurrently.
   * Only the first registration of each Chronology is retained by the
   * ConcurrentHashMap.
   *
   * @return true if the cache was initialized
   */
  private static boolean initCache() {
    if (CHRONOS_BY_ID.get("ISO") == null) {
      // Initialization is incomplete

      // Register built-in Chronologies
      registerChrono(HijrahChronology.INSTANCE);
      registerChrono(JapaneseChronology.INSTANCE);
      registerChrono(MinguoChronology.INSTANCE);
      registerChrono(ThaiBuddhistChronology.INSTANCE);

      // Register Chronologies from the ServiceLoader
      @SuppressWarnings("rawtypes")
      ServiceLoader<AbstractChronology> loader = ServiceLoader.load(AbstractChronology.class, null);
      for (AbstractChronology chrono : loader) {
        String id = chrono.getId();
        if (id.equals("ISO") || registerChrono(chrono) != null) {
          // Log the attempt to replace an existing Chronology
          PlatformLogger logger = PlatformLogger.getLogger("java.time.chrono");
          logger.warning("Ignoring duplicate Chronology, from ServiceLoader configuration " + id);
        }
      }

      // finally, register IsoChronology to mark initialization is complete
      registerChrono(IsoChronology.INSTANCE);
      return true;
    }
    return false;
  }

  //-----------------------------------------------------------------------

  /**
   * Obtains an instance of {@code Chronology} from a locale.
   * <p>
   * See {@link Chronology#ofLocale(Locale)}.
   *
   * @param locale the locale to use to obtain the calendar system, not null
   * @return the calendar system associated with the locale, not null
   * @throws java.time.DateTimeException if the locale-specified calendar cannot be found
   */
  static Chronology ofLocale(Locale locale) {
    Objects.requireNonNull(locale, "locale");
    String type = locale.getUnicodeLocaleType("ca");
    if (type == null || "iso".equals(type) || "iso8601".equals(type)) {
      return IsoChronology.INSTANCE;
    }
    // Not pre-defined; lookup by the type
    do {
      Chronology chrono = CHRONOS_BY_TYPE.get(type);
      if (chrono != null) {
        return chrono;
      }
      // If not found, do the initialization (once) and repeat the lookup
    } while (initCache());

    // Look for a Chronology using ServiceLoader of the Thread's ContextClassLoader
    // Application provided Chronologies must not be cached
    @SuppressWarnings("rawtypes")
    ServiceLoader<Chronology> loader = ServiceLoader.load(Chronology.class);
    for (Chronology chrono : loader) {
      if (type.equals(chrono.getCalendarType())) {
        return chrono;
      }
    }
    throw new DateTimeException("Unknown calendar system: " + type);
  }

  //-----------------------------------------------------------------------

  /**
   * Obtains an instance of {@code Chronology} from a chronology ID or
   * calendar system type.
   * <p>
   * See {@link Chronology#of(String)}.
   *
   * @param id the chronology ID or calendar system type, not null
   * @return the chronology with the identifier requested, not null
   * @throws java.time.DateTimeException if the chronology cannot be found
   */
  static Chronology of(String id) {
    Objects.requireNonNull(id, "id");
    do {
      Chronology chrono = of0(id);
      if (chrono != null) {
        return chrono;
      }
      // If not found, do the initialization (once) and repeat the lookup
    } while (initCache());

    // Look for a Chronology using ServiceLoader of the Thread's ContextClassLoader
    // Application provided Chronologies must not be cached
    @SuppressWarnings("rawtypes")
    ServiceLoader<Chronology> loader = ServiceLoader.load(Chronology.class);
    for (Chronology chrono : loader) {
      if (id.equals(chrono.getId()) || id.equals(chrono.getCalendarType())) {
        return chrono;
      }
    }
    throw new DateTimeException("Unknown chronology: " + id);
  }

  /**
   * Obtains an instance of {@code Chronology} from a chronology ID or
   * calendar system type.
   *
   * @param id the chronology ID or calendar system type, not null
   * @return the chronology with the identifier requested, or {@code null} if not found
   */
  private static Chronology of0(String id) {
    Chronology chrono = CHRONOS_BY_ID.get(id);
    if (chrono == null) {
      chrono = CHRONOS_BY_TYPE.get(id);
    }
    return chrono;
  }

  /**
   * Returns the available chronologies.
   * <p>
   * Each returned {@code Chronology} is available for use in the system.
   * The set of chronologies includes the system chronologies and
   * any chronologies provided by the application via ServiceLoader
   * configuration.
   *
   * @return the independent, modifiable set of the available chronology IDs, not null
   */
  static Set<Chronology> getAvailableChronologies() {
    initCache();       // force initialization
    HashSet<Chronology> chronos = new HashSet<>(CHRONOS_BY_ID.values());

    /// Add in Chronologies from the ServiceLoader configuration
    @SuppressWarnings("rawtypes")
    ServiceLoader<Chronology> loader = ServiceLoader.load(Chronology.class);
    for (Chronology chrono : loader) {
      chronos.add(chrono);
    }
    return chronos;
  }

  //-----------------------------------------------------------------------

  /**
   * Creates an instance.
   */
  protected AbstractChronology() {
  }

  //-----------------------------------------------------------------------

  /**
   * Resolves parsed {@code ChronoField} values into a date during parsing. <p> Most {@code
   * TemporalField} implementations are resolved using the resolve method on the field. By contrast,
   * the {@code ChronoField} class defines fields that only have meaning relative to the chronology.
   * As such, {@code ChronoField} date fields are resolved here in the context of a specific
   * chronology. <p> {@code ChronoField} instances are resolved by this method, which may be
   * overridden in subclasses. <ul> <li>{@code EPOCH_DAY} - If present, this is converted to a date
   * and all other date fields are then cross-checked against the date. <li>{@code PROLEPTIC_MONTH}
   * - If present, then it is split into the {@code YEAR} and {@code MONTH_OF_YEAR}. If the mode is
   * strict or smart then the field is validated. <li>{@code YEAR_OF_ERA} and {@code ERA} - If both
   * are present, then they are combined to form a {@code YEAR}. In lenient mode, the {@code
   * YEAR_OF_ERA} range is not validated, in smart and strict mode it is. The {@code ERA} is
   * validated for range in all three modes. If only the {@code YEAR_OF_ERA} is present, and the
   * mode is smart or lenient, then the last available era is assumed. In strict mode, no era is
   * assumed and the {@code YEAR_OF_ERA} is left untouched. If only the {@code ERA} is present, then
   * it is left untouched. <li>{@code YEAR}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} - If all
   * three are present, then they are combined to form a date. In all three modes, the {@code YEAR}
   * is validated. If the mode is smart or strict, then the month and day are validated. If the mode
   * is lenient, then the date is combined in a manner equivalent to creating a date on the first
   * day of the first month in the requested year, then adding the difference in months, then the
   * difference in days. If the mode is smart, and the day-of-month is greater than the maximum for
   * the year-month, then the day-of-month is adjusted to the last day-of-month. If the mode is
   * strict, then the three fields must form a valid date. <li>{@code YEAR} and {@code DAY_OF_YEAR}
   * - If both are present, then they are combined to form a date. In all three modes, the {@code
   * YEAR} is validated. If the mode is lenient, then the date is combined in a manner equivalent to
   * creating a date on the first day of the requested year, then adding the difference in days. If
   * the mode is smart or strict, then the two fields must form a valid date. <li>{@code YEAR},
   * {@code MONTH_OF_YEAR}, {@code ALIGNED_WEEK_OF_MONTH} and {@code ALIGNED_DAY_OF_WEEK_IN_MONTH} -
   * If all four are present, then they are combined to form a date. In all three modes, the {@code
   * YEAR} is validated. If the mode is lenient, then the date is combined in a manner equivalent to
   * creating a date on the first day of the first month in the requested year, then adding the
   * difference in months, then the difference in weeks, then in days. If the mode is smart or
   * strict, then the all four fields are validated to their outer ranges. The date is then combined
   * in a manner equivalent to creating a date on the first day of the requested year and month,
   * then adding the amount in weeks and days to reach their values. If the mode is strict, the date
   * is additionally validated to check that the day and week adjustment did not change the month.
   * <li>{@code YEAR}, {@code MONTH_OF_YEAR}, {@code ALIGNED_WEEK_OF_MONTH} and {@code DAY_OF_WEEK}
   * - If all four are present, then they are combined to form a date. The approach is the same as
   * described above for years, months and weeks in {@code ALIGNED_DAY_OF_WEEK_IN_MONTH}. The
   * day-of-week is adjusted as the next or same matching day-of-week once the years, months and
   * weeks have been handled. <li>{@code YEAR}, {@code ALIGNED_WEEK_OF_YEAR} and {@code
   * ALIGNED_DAY_OF_WEEK_IN_YEAR} - If all three are present, then they are combined to form a date.
   * In all three modes, the {@code YEAR} is validated. If the mode is lenient, then the date is
   * combined in a manner equivalent to creating a date on the first day of the requested year, then
   * adding the difference in weeks, then in days. If the mode is smart or strict, then the all
   * three fields are validated to their outer ranges. The date is then combined in a manner
   * equivalent to creating a date on the first day of the requested year, then adding the amount in
   * weeks and days to reach their values. If the mode is strict, the date is additionally validated
   * to check that the day and week adjustment did not change the year. <li>{@code YEAR}, {@code
   * ALIGNED_WEEK_OF_YEAR} and {@code DAY_OF_WEEK} - If all three are present, then they are
   * combined to form a date. The approach is the same as described above for years and weeks in
   * {@code ALIGNED_DAY_OF_WEEK_IN_YEAR}. The day-of-week is adjusted as the next or same matching
   * day-of-week once the years and weeks have been handled. </ul> <p> The default implementation is
   * suitable for most calendar systems. If {@link java.time.temporal.ChronoField#YEAR_OF_ERA} is
   * found without an {@link java.time.temporal.ChronoField#ERA} then the last era in {@link
   * #eras()} is used. The implementation assumes a 7 day week, that the first day-of-month has the
   * value 1, that first day-of-year has the value 1, and that the first of the month and year
   * always exists.
   *
   * @param fieldValues the map of fields to values, which can be updated, not null
   * @param resolverStyle the requested type of resolve, not null
   * @return the resolved date, null if insufficient information to create a date
   * @throws java.time.DateTimeException if the date cannot be resolved, typically because of a
   * conflict in the input data
   */
  @Override
  public ChronoLocalDate resolveDate(Map<TemporalField, Long> fieldValues,
      ResolverStyle resolverStyle) {
    // check epoch-day before inventing era
    if (fieldValues.containsKey(EPOCH_DAY)) {
      return dateEpochDay(fieldValues.remove(EPOCH_DAY));
    }

    // fix proleptic month before inventing era
    resolveProlepticMonth(fieldValues, resolverStyle);

    // invent era if necessary to resolve year-of-era
    ChronoLocalDate resolved = resolveYearOfEra(fieldValues, resolverStyle);
    if (resolved != null) {
      return resolved;
    }

    // build date
    if (fieldValues.containsKey(YEAR)) {
      if (fieldValues.containsKey(MONTH_OF_YEAR)) {
        if (fieldValues.containsKey(DAY_OF_MONTH)) {
          return resolveYMD(fieldValues, resolverStyle);
        }
        if (fieldValues.containsKey(ALIGNED_WEEK_OF_MONTH)) {
          if (fieldValues.containsKey(ALIGNED_DAY_OF_WEEK_IN_MONTH)) {
            return resolveYMAA(fieldValues, resolverStyle);
          }
          if (fieldValues.containsKey(DAY_OF_WEEK)) {
            return resolveYMAD(fieldValues, resolverStyle);
          }
        }
      }
      if (fieldValues.containsKey(DAY_OF_YEAR)) {
        return resolveYD(fieldValues, resolverStyle);
      }
      if (fieldValues.containsKey(ALIGNED_WEEK_OF_YEAR)) {
        if (fieldValues.containsKey(ALIGNED_DAY_OF_WEEK_IN_YEAR)) {
          return resolveYAA(fieldValues, resolverStyle);
        }
        if (fieldValues.containsKey(DAY_OF_WEEK)) {
          return resolveYAD(fieldValues, resolverStyle);
        }
      }
    }
    return null;
  }

  void resolveProlepticMonth(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
    Long pMonth = fieldValues.remove(PROLEPTIC_MONTH);
    if (pMonth != null) {
      if (resolverStyle != ResolverStyle.LENIENT) {
        PROLEPTIC_MONTH.checkValidValue(pMonth);
      }
      // first day-of-month is likely to be safest for setting proleptic-month
      // cannot add to year zero, as not all chronologies have a year zero
      ChronoLocalDate chronoDate = dateNow()
          .with(DAY_OF_MONTH, 1).with(PROLEPTIC_MONTH, pMonth);
      addFieldValue(fieldValues, MONTH_OF_YEAR, chronoDate.get(MONTH_OF_YEAR));
      addFieldValue(fieldValues, YEAR, chronoDate.get(YEAR));
    }
  }

  ChronoLocalDate resolveYearOfEra(Map<TemporalField, Long> fieldValues,
      ResolverStyle resolverStyle) {
    Long yoeLong = fieldValues.remove(YEAR_OF_ERA);
    if (yoeLong != null) {
      Long eraLong = fieldValues.remove(ERA);
      int yoe;
      if (resolverStyle != ResolverStyle.LENIENT) {
        yoe = range(YEAR_OF_ERA).checkValidIntValue(yoeLong, YEAR_OF_ERA);
      } else {
        yoe = Math.toIntExact(yoeLong);
      }
      if (eraLong != null) {
        Era eraObj = eraOf(range(ERA).checkValidIntValue(eraLong, ERA));
        addFieldValue(fieldValues, YEAR, prolepticYear(eraObj, yoe));
      } else {
        if (fieldValues.containsKey(YEAR)) {
          int year = range(YEAR).checkValidIntValue(fieldValues.get(YEAR), YEAR);
          ChronoLocalDate chronoDate = dateYearDay(year, 1);
          addFieldValue(fieldValues, YEAR, prolepticYear(chronoDate.getEra(), yoe));
        } else if (resolverStyle == ResolverStyle.STRICT) {
          // do not invent era if strict
          // reinstate the field removed earlier, no cross-check issues
          fieldValues.put(YEAR_OF_ERA, yoeLong);
        } else {
          List<Era> eras = eras();
          if (eras.isEmpty()) {
            addFieldValue(fieldValues, YEAR, yoe);
          } else {
            Era eraObj = eras.get(eras.size() - 1);
            addFieldValue(fieldValues, YEAR, prolepticYear(eraObj, yoe));
          }
        }
      }
    } else if (fieldValues.containsKey(ERA)) {
      range(ERA).checkValidValue(fieldValues.get(ERA), ERA);  // always validated
    }
    return null;
  }

  ChronoLocalDate resolveYMD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
    int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
    if (resolverStyle == ResolverStyle.LENIENT) {
      long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
      long days = Math.subtractExact(fieldValues.remove(DAY_OF_MONTH), 1);
      return date(y, 1, 1).plus(months, MONTHS).plus(days, DAYS);
    }
    int moy = range(MONTH_OF_YEAR)
        .checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
    ValueRange domRange = range(DAY_OF_MONTH);
    int dom = domRange.checkValidIntValue(fieldValues.remove(DAY_OF_MONTH), DAY_OF_MONTH);
    if (resolverStyle == ResolverStyle.SMART) {  // previous valid
      try {
        return date(y, moy, dom);
      } catch (DateTimeException ex) {
        return date(y, moy, 1).with(TemporalAdjusters.lastDayOfMonth());
      }
    }
    return date(y, moy, dom);
  }

  ChronoLocalDate resolveYD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
    int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
    if (resolverStyle == ResolverStyle.LENIENT) {
      long days = Math.subtractExact(fieldValues.remove(DAY_OF_YEAR), 1);
      return dateYearDay(y, 1).plus(days, DAYS);
    }
    int doy = range(DAY_OF_YEAR).checkValidIntValue(fieldValues.remove(DAY_OF_YEAR), DAY_OF_YEAR);
    return dateYearDay(y, doy);  // smart is same as strict
  }

  ChronoLocalDate resolveYMAA(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
    int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
    if (resolverStyle == ResolverStyle.LENIENT) {
      long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
      long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), 1);
      long days = Math.subtractExact(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_MONTH), 1);
      return date(y, 1, 1).plus(months, MONTHS).plus(weeks, WEEKS).plus(days, DAYS);
    }
    int moy = range(MONTH_OF_YEAR)
        .checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
    int aw = range(ALIGNED_WEEK_OF_MONTH)
        .checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), ALIGNED_WEEK_OF_MONTH);
    int ad = range(ALIGNED_DAY_OF_WEEK_IN_MONTH)
        .checkValidIntValue(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_MONTH),
            ALIGNED_DAY_OF_WEEK_IN_MONTH);
    ChronoLocalDate date = date(y, moy, 1).plus((aw - 1) * 7 + (ad - 1), DAYS);
    if (resolverStyle == ResolverStyle.STRICT && date.get(MONTH_OF_YEAR) != moy) {
      throw new DateTimeException(
          "Strict mode rejected resolved date as it is in a different month");
    }
    return date;
  }

  ChronoLocalDate resolveYMAD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
    int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
    if (resolverStyle == ResolverStyle.LENIENT) {
      long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
      long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), 1);
      long dow = Math.subtractExact(fieldValues.remove(DAY_OF_WEEK), 1);
      return resolveAligned(date(y, 1, 1), months, weeks, dow);
    }
    int moy = range(MONTH_OF_YEAR)
        .checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
    int aw = range(ALIGNED_WEEK_OF_MONTH)
        .checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), ALIGNED_WEEK_OF_MONTH);
    int dow = range(DAY_OF_WEEK).checkValidIntValue(fieldValues.remove(DAY_OF_WEEK), DAY_OF_WEEK);
    ChronoLocalDate date = date(y, moy, 1).plus((aw - 1) * 7, DAYS)
        .with(nextOrSame(DayOfWeek.of(dow)));
    if (resolverStyle == ResolverStyle.STRICT && date.get(MONTH_OF_YEAR) != moy) {
      throw new DateTimeException(
          "Strict mode rejected resolved date as it is in a different month");
    }
    return date;
  }

  ChronoLocalDate resolveYAA(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
    int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
    if (resolverStyle == ResolverStyle.LENIENT) {
      long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), 1);
      long days = Math.subtractExact(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_YEAR), 1);
      return dateYearDay(y, 1).plus(weeks, WEEKS).plus(days, DAYS);
    }
    int aw = range(ALIGNED_WEEK_OF_YEAR)
        .checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), ALIGNED_WEEK_OF_YEAR);
    int ad = range(ALIGNED_DAY_OF_WEEK_IN_YEAR)
        .checkValidIntValue(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_YEAR),
            ALIGNED_DAY_OF_WEEK_IN_YEAR);
    ChronoLocalDate date = dateYearDay(y, 1).plus((aw - 1) * 7 + (ad - 1), DAYS);
    if (resolverStyle == ResolverStyle.STRICT && date.get(YEAR) != y) {
      throw new DateTimeException(
          "Strict mode rejected resolved date as it is in a different year");
    }
    return date;
  }

  ChronoLocalDate resolveYAD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
    int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
    if (resolverStyle == ResolverStyle.LENIENT) {
      long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), 1);
      long dow = Math.subtractExact(fieldValues.remove(DAY_OF_WEEK), 1);
      return resolveAligned(dateYearDay(y, 1), 0, weeks, dow);
    }
    int aw = range(ALIGNED_WEEK_OF_YEAR)
        .checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), ALIGNED_WEEK_OF_YEAR);
    int dow = range(DAY_OF_WEEK).checkValidIntValue(fieldValues.remove(DAY_OF_WEEK), DAY_OF_WEEK);
    ChronoLocalDate date = dateYearDay(y, 1).plus((aw - 1) * 7, DAYS)
        .with(nextOrSame(DayOfWeek.of(dow)));
    if (resolverStyle == ResolverStyle.STRICT && date.get(YEAR) != y) {
      throw new DateTimeException(
          "Strict mode rejected resolved date as it is in a different year");
    }
    return date;
  }

  ChronoLocalDate resolveAligned(ChronoLocalDate base, long months, long weeks, long dow) {
    ChronoLocalDate date = base.plus(months, MONTHS).plus(weeks, WEEKS);
    if (dow > 7) {
      date = date.plus((dow - 1) / 7, WEEKS);
      dow = ((dow - 1) % 7) + 1;
    } else if (dow < 1) {
      date = date.plus(Math.subtractExact(dow, 7) / 7, WEEKS);
      dow = ((dow + 6) % 7) + 1;
    }
    return date.with(nextOrSame(DayOfWeek.of((int) dow)));
  }

  /**
   * Adds a field-value pair to the map, checking for conflicts.
   * <p>
   * If the field is not already present, then the field-value pair is added to the map.
   * If the field is already present and it has the same value as that specified, no action occurs.
   * If the field is already present and it has a different value to that specified, then
   * an exception is thrown.
   *
   * @param field the field to add, not null
   * @param value the value to add, not null
   * @throws java.time.DateTimeException if the field is already present with a different value
   */
  void addFieldValue(Map<TemporalField, Long> fieldValues, ChronoField field, long value) {
    Long old = fieldValues.get(field);  // check first for better error message
    if (old != null && old.longValue() != value) {
      throw new DateTimeException(
          "Conflict found: " + field + " " + old + " differs from " + field + " " + value);
    }
    fieldValues.put(field, value);
  }

  //-----------------------------------------------------------------------

  /**
   * Compares this chronology to another chronology.
   * <p>
   * The comparison order first by the chronology ID string, then by any
   * additional information specific to the subclass.
   * It is "consistent with equals", as defined by {@link Comparable}.
   *
   * @param other the other chronology to compare to, not null
   * @return the comparator value, negative if less, positive if greater
   * @implSpec This implementation compares the chronology ID. Subclasses must compare any
   * additional state that they store.
   */
  @Override
  public int compareTo(Chronology other) {
    return getId().compareTo(other.getId());
  }

  /**
   * Checks if this chronology is equal to another chronology.
   * <p>
   * The comparison is based on the entire state of the object.
   *
   * @param obj the object to check, null returns false
   * @return true if this is equal to the other chronology
   * @implSpec This implementation checks the type and calls {@link #compareTo(java.time.chrono.Chronology)}.
   */
  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj instanceof AbstractChronology) {
      return compareTo((AbstractChronology) obj) == 0;
    }
    return false;
  }

  /**
   * A hash code for this chronology.
   * <p>
   * The hash code should be based on the entire state of the object.
   *
   * @return a suitable hash code
   * @implSpec This implementation is based on the chronology ID and class. Subclasses should add
   * any additional state that they store.
   */
  @Override
  public int hashCode() {
    return getClass().hashCode() ^ getId().hashCode();
  }

  //-----------------------------------------------------------------------

  /**
   * Outputs this chronology as a {@code String}, using the chronology ID.
   *
   * @return a string representation of this chronology, not null
   */
  @Override
  public String toString() {
    return getId();
  }

  //-----------------------------------------------------------------------

  /**
   * Writes the Chronology using a
   * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
   * <pre>
   *  out.writeByte(1);  // identifies this as a Chronology
   *  out.writeUTF(getId());
   * </pre>
   *
   * @return the instance of {@code Ser}, not null
   */
  Object writeReplace() {
    return new Ser(Ser.CHRONO_TYPE, this);
  }

  /**
   * Defend against malicious streams.
   *
   * @param s the stream to read
   * @throws java.io.InvalidObjectException always
   */
  private void readObject(ObjectInputStream s) throws ObjectStreamException {
    throw new InvalidObjectException("Deserialization via serialization delegate");
  }

  void writeExternal(DataOutput out) throws IOException {
    out.writeUTF(getId());
  }

  static Chronology readExternal(DataInput in) throws IOException {
    String id = in.readUTF();
    return Chronology.of(id);
  }

}
